Commit 72237693 authored by Manas's avatar Manas Committed by Andrew Morton
Browse files

mm/memory.c: simplify pfnmap_lockdep_assert 

Use local `mapping' to reduce the pointer chasing.

akpm: extracted from a bugfix which Linus fixed with b1b46751 ("mm:
fix follow_pfnmap API lockdep assert").

Link: https://lkml.kernel.org/r/20241004-fix-null-deref-v4-1-d0a8ec01ac85@iiitd.ac.in


Signed-off-by: default avatarManas <manas18244@iiitd.ac.in>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Anup Sharma <anupnewsmail@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ed265529

mm/memory.c

+1 −1
Original line number Diff line number Diff line
@@ -6388,7 +6388,7 @@ static inline void pfnmap_lockdep_assert(struct vm_area_struct *vma) 
	struct address_space *mapping = file ? file->f_mapping : NULL;



	if (mapping)

		lockdep_assert(lockdep_is_held(&vma->vm_file->f_mapping->i_mmap_rwsem) ||

		lockdep_assert(lockdep_is_held(&mapping->i_mmap_rwsem) ||

			       lockdep_is_held(&vma->vm_mm->mmap_lock));

	else

		lockdep_assert(lockdep_is_held(&vma->vm_mm->mmap_lock));